DE102022002837A1 - lighting device - Google Patents

Abstract

The present invention relates to a lighting device, comprising at least one circuit board for accommodating electronic components, at least one metal core circuit board for accommodating illuminants on a free top side of the metal core circuit board for generating light, wherein the at least one circuit board and the at least one metal core circuit board are in an active operating state are electrically connected to each other via wiring means. According to the invention it is provided that the at least one metal core circuit board comprises a recess and/or recess and the lighting device comprises an adapter element, wherein at least in the active operating state the wiring means are freely arranged in the one recess and/or recess and an electrical connection between the at least one Form the circuit board and the adapter element, the adapter element in turn realizing an electrical connection to the at least one metal core circuit board, in particular to the lamps.

Description

The present invention relates to a lighting device according to the preamble of claim 1.

Lighting devices comprising light-emitting diodes are generally known from the prior art. Light-emitting diodes (LED) differ from classic light bulbs in their longer operating times, more compact dimensions while producing the same light intensity and lower energy consumption. Light-emitting diodes can also be manufactured at ever lower costs, which explains the current dominance of light-emitting diodes for lighting applications.

A light-emitting diode is a semiconductor component with a characteristic voltage-current characteristic (UI characteristic), which describes a specific relationship between the diode voltage dropping across the light-emitting diode and the diode current flowing through the light-emitting diode. The brightness of a light-emitting diode is directly dependent on the diode current. The diode voltage, which is also referred to as threshold, forward or forward voltage, depends not only on the diode current but also on the color of the LED and the specific type of LED. Light-emitting diodes are often manufactured as SMD components, which can then be mounted directly on a circuit board to form a light source with small dimensions.

Regardless of whether a pulsed lighting operation or a continuous lighting operation is implemented, the light-emitting diodes must be protected from high temperatures in order to avoid damage or even complete destruction caused by the heat loss generated in the light-emitting diodes. Cooling and/or temperature management therefore plays a crucial role in ensuring that the heat loss that is harmful to the light-emitting diodes can be carried away from the components as efficiently as possible.

A lighting device known from the prior art therefore comprises a metal core circuit board equipped with a large number of lamps, in particular light-emitting diodes, since the heat-conducting metal core can be used to dissipate the heat loss from the lamps particularly efficiently. Other electronic components - for example for generating the control pulses and/or for external communication - are arranged on a classic circuit board, as this can be manufactured more cost-effectively compared to a metal core circuit board. For electrically interconnecting the classic circuit board with the metal core circuit board, different wiring means are generally known in order to electrically connect the components on both circuit boards to one another. However, due to the electrically conductive core of the metal core printed circuit board, the wiring means cannot be carried out cost-effectively simply by drilling holes to create plated-through holes - for example using push-through components. Although there are already specially designed wiring devices for this purpose with an additional insulation layer, these solutions are technically complex and expensive. Furthermore, these special solutions cannot be manufactured automatically by many traditional suppliers, which further increases costs. In addition, the known wiring means are designed in such a way that the end sections resting on the metal core circuit boards clearly protrude beyond the height of the light-emitting diodes, which is a major disadvantage, particularly in applications with limited installation space.

The object of the present invention is based on overcoming the disadvantages known from the prior art. Preferably, the object of the present invention is to provide a lighting device that inexpensively brings a metal core circuit board into effective electrical and/or mechanical connection with a classic circuit board, it being particularly preferred if the overall height of the lighting device is not negatively influenced.

This object is achieved by a device according to the invention according to claim 1.

Advantageous developments of the invention are described in the subclaims. All combinations of at least two of the features disclosed in the description, the claims and/or the figures fall within the scope of the invention.

The present invention comprises a lighting device with at least one circuit board for accommodating electronic and/or electrical components and with at least one metal core circuit board for accommodating lamps on a free top side of the metal core circuit board for generating light, the lamps preferably being provided by a light-emitting diode, particularly preferably are formed by a light-emitting diode in SMD design. The lighting device is designed in such a way that the lamps arranged on the top generate light, which is then emitted onto an area hereinafter referred to as the lighting space, which extends in front of the top of the metal core guide plate.

According to the invention, the at least one circuit board and the at least one metal core Circuit board in an active operating state of the lighting device, which is in particular formed by a pulsed and / or constant lighting operation, electrically and in particular mechanically connected to one another via wiring means comprised by the lighting device.

Specifically, the at least one circuit board and the at least one metal core circuit board are arranged and/or positioned relative to one another in such a way that the at least one circuit board extends in an area behind the metal core circuit board. This rear area adjoins the outer underside of the metal core circuit board, which is formed opposite the top side of the metal core circuit board that accommodates the light-emitting diodes. In other words, the at least one metal core circuit board is arranged between the at least one circuit board and the lighting space, which is illuminated by the lamps in the active operating state.

According to the invention, the wiring means comprise at least two conductor paths which are electrically insulated from one another and enable the transmission of an electrical current and/or an electrical voltage. The wiring means, in particular the large number of conductor paths, are preferably designed to be rigid and/or inflexible. Alternatively, however, a flexible design of the wiring means is also possible, in which case it is further provided in this context that the wiring means comprise a positioning unit which is designed in such a way that a voltage flashover does not occur due to a central and/or circumferentially spaced positioning of the wiring means can come between the wiring means and the other electrical and / or electronic components of the circuit board, the metal core circuit board or the metal core of the metal core circuit board.

According to the invention, the at least one metal core circuit board comprises a recess and/or recess, in particular a material recess and/or material recess. In the context of the present invention, the recess and/or recess is dimensioned and/or designed in such a way that the wiring means, in particular a plurality of the conductor paths of the wiring means, can be guided through the at least one metal core circuit board without a minimum distance between the Metal core and the conductor paths of the wiring means carrying a current and/or a voltage. The minimum distance is in turn dimensioned so that a required insulation resistance is maintained, which prevents voltage flashover due to the potential difference, in particular there is no insulating material but only the ambient air in the gap.

In other words, a recess accommodates the entire wiring means or a subgroup of the wiring means, the subgroup of the wiring means comprising at least two, preferably at least three, particularly preferably at least four, very particularly preferably at least eight conductor paths that are electrically insulated from one another.

Furthermore, the lighting device according to the invention comprises an adapter element, wherein at least in the active operating state of the lighting device, the wiring means are arranged freely in the one recess and/or recess, in particular spaced from the metal core circuit board on the circumference, and an electrical connection between the at least one circuit board, in particular the conductor tracks the at least one circuit board and/or the electronic components and/or components and/or components of the at least one circuit board, and the adapter element, wherein the adapter element in turn realizes an electrical connection to the at least one metal core circuit board, in particular to the top of the metal core circuit board.

The wiring means, in particular the plurality of conductor paths of the wiring means, are in effective contact with the at least one printed circuit board at a first end. This active contact is preferably formed by a detachable or non-detachable electrical connection between the conductor paths of the wiring means and the individual conductor tracks of the circuit board. Furthermore, according to the invention, the wiring means are then guided centrally and/or centrally through the recess and/or recess, so that the second end of the wiring means, i.e. the second end of the at least two conductor paths, ends on the opposite side, in particular on the top side of the metal core circuit board .

The second end of the wiring means is in effective contact with the adapter element. This active contact is preferably formed by a detachable or non-detachable electrical connection between the conductor paths of the wiring means and the adapter element, in particular individual conductor tracks of the adapter element. The adapter element, in particular the individual conductor tracks of the adapter element, are then in effective contact with the metal core circuit board, in particular the conductor tracks of the metal core circuit board. According to the invention, an electrical connection between the conductor tracks of the little at least one circuit board and the conductor tracks of the at least one metal core circuit board are produced in order to transmit electrical signals, in particular a control and / or supply current and / or a control and / or supply voltage.

As part of a further development, the wiring means are designed as a pin strip. The pin strip comprises a plurality of pin contacts arranged in a row, which are designed to be particularly rigid and/or inflexible and without circumferential insulation. The pin strip is preferably detachably connected to the circuit board at a first end via a socket strip or a plug-in element with the same effect. The second end of the pin header, in particular all of the pin contacts of the pin header at the second end, each protrude into holes that are formed in the adapter element. The second end is preferably an inseparable connection, since the pin contacts are fixed in the hole using solder and therefore cannot be separated from the adapter element without tools.

The preferred configuration as a pin strip has the advantage that the wiring means are rigid. A central and/or central positioning of the wiring means within the recess can therefore be implemented without additional support and/or positioning elements. Furthermore, a pin header is a standard component that can therefore be obtained at low cost.

Furthermore, it is further provided that the recess and/or recess is dimensioned such that a required insulation resistance between the wiring means and the metal core circuit board, in particular a metal core of the metal core circuit board, is maintained in order to avoid voltage flashover. The preferred dimensioning of the recess and/or recess in such a way that the insulation resistance between the conductor paths of the wiring means and the metal core is maintained results in no additional insulating material, in particular an electrical insulator, in the recess and/or recess between the wiring means and the Metal core circuit board needs to be positioned. This also advantageously leads to lower material costs and reduces manufacturing costs.

In a further development, it is provided in this context that the pin strip comprises at least two pin contacts that are electrically insulated from one another and spatially positioned in a row and/or along an imaginary line. Furthermore, the pin contacts between the first end and the second end are preferably designed to be rigid and/or inflexible and in particular do not include any circumferential insulation. Advantageously, the material costs can be further reduced because it is a standard component.

Furthermore, in a further development of the invention it is provided that the adapter element is designed as a wiring board or as a circuit board. The plate-shaped design of the adapter element as a wiring board or as a printed circuit board advantageously leads to a particularly small extension of the adapter element, which is why the lighting device is compact. The lighting device can therefore also be used in applications that only provide a small amount of space, i.e. a low overall height, to accommodate the lighting device.

In this context, the circuit board, in particular the adapter circuit board, is preferably designed as a single layer. Alternatively, the circuit board, i.e. the adapter circuit board, can also be designed in multiple layers.

By designing the adapter element as an adapter circuit board, it is advantageous to rely on an established technology with defined and/or standardized standards, which is why numerous suppliers and/or manufacturers can be used for the procurement and/or production of the components. In addition to low costs for implementing the present embodiment, this also leads to good availability, since individual suppliers can be replaced thanks to the standardized technology.

In a further development, it is also planned in this context that the wiring board or the circuit board comprises a plurality of round openings and/or bores for receiving and electrically connecting, in particular through-plating, the wiring means, in particular the pin strip. Thus, the pin strip at the second end can protrude directly into the individual openings and be permanently soldered there in order to form a mechanical fixation and an electrical contact with the conductor tracks of the wiring board and/or the circuit board of the adapter element.

In addition, a further development provides that the at least one circuit board and/or the at least one metal core circuit board have an annular contour in plan view.

The annular design means that the lighting device can be arranged around the lens of a camera in order to form an illumination space that enables uniform illumination of a detection area of the camera.

It is also preferably provided that the wiring board, in particular the circuit board forming the adapter element, comprises a plurality of contact areas on at least one side surface. These contact areas are designed and/or positioned in the at least one side surface so that in the active operating state an electrical connection can be established to a plurality of solder pads formed on the top side of the at least one metal core circuit board. An electrical connection between the adapter element and the metal core circuit board can thus advantageously be realized directly using solder. Advantageously, all of the conductor tracks of the at least one printed circuit board can be electrically connected to the corresponding conductor tracks of the at least one metal core printed circuit board.

Since the length of the wiring board or the circuit board forming the adapter element correlates with the length of the pin strip and thus the number of pin contacts, there is always sufficient free space in the side surfaces to form the individual contact areas. In this context, the electrical contact can advantageously be realized using only solder, which in turn contributes to the low manufacturing costs of the lighting device.

In a further development, it is provided that the contact areas comprise an electrically conductive layer, in particular a metal layer, on the outside. Advantageously, the electrical contact between the wiring board or the circuit board forming the adapter element and the soldering pads of the metal core circuit board can thus be established particularly easily and reliably.

In addition, as part of a further development, it is provided that the contact areas each comprise an arcuate section which is aligned radially inwards with respect to the circuit board forming the adapter element. The final assembly is advantageously made easier, since after positioning the wiring board or the circuit board forming the adapter element on the metal core circuit board, all soldering areas to be realized become clearly visible due to the outer contour, which makes manual production, especially by inexperienced personnel, easier.

Finally, in a further development, it is also provided that the recess and/or recess in the metal core circuit board is designed to be closed on the circumference. Additionally or alternatively, it is preferably provided that the inner contour of the recess and/or recess replicates the outer contour of the wiring means and/or correlates with it and/or these are designed to be geometrically similar.

This advantageously leads to a constant insulation resistance, since the minimum distance can always be maintained.

The invention is explained in more detail below by way of example with reference to the drawings. The combination of features exemplified in the embodiments shown can be supplemented by further features in accordance with the above statements in accordance with the properties of the lighting device according to the invention that are necessary for a specific application. Also in accordance with the above statements, individual features can be omitted from the described embodiments if the effect of this feature is not important in a specific application.

In the drawings, elements with the same function and/or the same structure are always designated with the same reference numerals.

• 1: eine perspektivische Darstellung einer erfindungsgemäßen Beleuchtungsvorrichtung gemäß einer bevorzugten Ausführungsform,
• 2: eine perspektivische Darstellung der bereits bekannten Metallkernleiterplatte in Einzeldarstellung aus einer oberen Blickrichtung,
• 3: eine perspektivische Darstellung der Metallkernleiterplatte aus einer unteren Blickrichtung und
• 4: eine perspektivische Darstellung der Metallkernleiterplatte aus einer oberen Blickrichtung im vergrößerten Maßstab.

Show it:

• 1 : a perspective view of a lighting device according to the invention according to a preferred embodiment,
• 2 : a perspective view of the already known metal core circuit board in an individual view from an upper viewing direction,
• 3 : a perspective view of the metal core circuit board from a lower viewing direction and
• 4 : a perspective view of the metal core circuit board from an upper viewing direction on an enlarged scale.

The 1 shows a perspective view of a lighting device 1 according to the invention according to a preferred embodiment. The lighting device 1 comprises a circuit board 2, which has an annular configuration and/or a hollow cylindrical floor plan, and four metal core circuit boards, with only one metal core circuit board 3 being shown in the illustration, the floor plan of which forms a partial area of a ring. The four metal core circuit boards together form an annular floor plan in order to be arranged on the circumference of a lens of a camera and thus to achieve uniform illumination of a detection area of the camera.

The metal core circuit board 3 includes an outer top with lamps 4 for illuminating a lighting space located in the graphic representation above the lighting device 1 extends.

In the present case, the lamps 4 are designed as light-emitting diodes 5 in SMD design, which are arranged directly on the metal core circuit board 3, which is why the heat loss from the light-emitting diodes 5 that arises in the active operating state via the metal core 10 of the metal core circuit board 3 comes largely from the SMD light-emitting diodes 5 can be derived. In other words, the metal core 10 of the metal core circuit board 3, which is not shown in detail, is thermally coupled to the SMD light-emitting diodes 5 in order to dissipate the heat loss from the light-emitting diodes 5.

The metal core circuit board 3 and the annular circuit board 2 are arranged parallel to each other, with the circuit board 2 positioned relative to the metal core circuit board 3 so that the circuit board 2 is arranged on the side of the metal core circuit board 3 that is opposite to the top of the metal core circuit board 3.

The metal core circuit board 3 and the annular circuit board 2 are electrically connected to each other via wiring means 6. In the exemplary embodiment shown, the wiring means 6 are designed as a pin strip 9, the pin strip 9 comprising a plurality of individual pin contacts that are electrically insulated from one another. The elongated pin contacts are rigid, with the length of the pin contacts being essentially orthogonal to the surface extent of the circuit board 2 and the metal core circuit board 3.

The metal core circuit board 3 includes a recess 7 (cf. 3 ), which is formed by a material recess in the metal core circuit board 3. At least in the active operating state of the lighting device 1, the pin header 9 is arranged within the recess 7 in such a way that all pin contacts of the pin header 9 are spaced from the metal core 10 by at least a minimum distance. The minimum distance is chosen and/or dimensioned so that no voltage flashover can occur between the pin contacts carrying a voltage and/or a current and the metal core 10 of the metal core circuit board 3 in the active operating state of the lighting device 1.

Furthermore, it can be seen from the illustration that the lighting device 1 according to the invention comprises an adapter element 8, which in the present case is formed by a flat circuit board 12. The circuit board 12 includes several round holes 17a-c. The holes 17a-c are designed in terms of their dimensioning and/or positioning in such a way that each hole 17a-c accommodates exactly one pin contact of the pin strip 9. The pin contacts are electrically connected to the circuit board 12 via solder at a second end in the holes 17a-c and are thereby also mechanically fixed there. At the opposite end, the pin contacts of the pin strip 9 open into a plug receptacle 11, in particular a socket strip, which is why the electrical contact between the pin strip 9 and the at least one circuit board 3 is designed to be detachable.

The circuit board 12 forming the adapter element 8 comprises a plurality of conductor tracks which establish an electrical connection between one of the holes 17a-c and one of the contact areas 13a-c. The contact areas 13a-c are formed in the side surface of the circuit board 12 by circular recesses. The circular recesses, which can in particular also be referred to as arcuate sections, enable the circuit board 12 to be electrically contacted with the metal core circuit board 3. For this purpose, the metal core circuit board 3 comprises soldering pads which are formed on the top.

The 2 shows a perspective individual view of the metal core circuit board 3 from an oblique upper side view. On the top of the metal core circuit board 3, the circuit board 12 is fixed, the contact areas 13a-c of which are connected to the soldering pads of the metal core circuit board 3. Furthermore, the top of the metal core circuit board 3 is equipped with several light-emitting diodes 5, which are arranged in two circular rows.

The circuit board 12 includes the already mentioned contact areas 13a-c, which are formed in all side surfaces of the circuit board 12 by arcuate material recesses in the circuit board 12. The circuit board 12, in particular the conductor tracks formed in the circuit board 12, can advantageously be electrically connected to the conductor tracks of the metal core circuit board 3 via the lateral contact areas 13a-c. For this purpose, the metal core circuit board 3 includes the solder pads already mentioned, which are not shown in detail in the figure.

The pin strip 9, which comprises the plurality of contact pins arranged in two rows, are arranged in the bores 17a-c, with the end sections of the pin strip 9 of the circuit board 12 protruding in areas in order to carry out test measurements, in particular during commissioning.

The 3 shows a perspective individual view of the 2 known metal core circuit board 3 from a diagonally lower side view. From this perspective, the recess and/or recess 7 is clearly visible, which is in the metal core circuit board 3 is formed. The recess 7 comprises a closed contour, with the pin strip 9 being arranged in the recess 7 in such a way that all contact pins are spaced from the metal core 10 of the metal core circuit board 3 over a minimum distance so that voltage flashover does not occur. Advantageously, several electrical connections between the annular circuit board 2 and the light-emitting diodes 5 can be implemented in a surprisingly simple manner.

The 4 shows a partial section of the 2 in an enlarged view. The partial section shows the circuit board 12 fixed on the metal core circuit board 3 on an enlarged scale. It now becomes clear that the pin strip 9 forming the wiring means 6 comprises a total of ten contact pins, which are arranged in two adjacent rows. Furthermore, the ten holes 17a-c, which are only partially numbered, are visible and are positioned in the circuit board 12 in such a way that all contact pins of the pin strip 9 are each arranged in a hole 17a-c. The electrical contact can therefore advantageously be realized cost-effectively using solder.

In addition, the ten contact areas 13a-c can also be seen, which are formed in the partially numbered four side surfaces 14a-b of the circuit board 12 by the arcuate sections 16 and are also only partially provided with reference numbers. The arcuate sections 16 comprise an electrically conductive layer 15, which in the present case is formed by a metal layer.

Below the contact areas 13a-c, the metal core circuit board 3 includes ten solder pads, not shown in detail, which enable electrical contacting of the contact areas 13a-c with the conductor tracks of the metal core circuit board 3 using solder.

As a result, the present invention makes it possible to realize electrical contact between a printed circuit board and a metal core printed circuit board in a surprisingly simple but cleverly combined manner in order to provide a lighting device that can be produced inexpensively.

Claims (10)

Lighting device (1), comprising at least one circuit board (2) for accommodating electronic components, at least one metal core circuit board (3) for accommodating lamps (4) on a free top side of the metal core circuit board (3) for generating light, wherein the at least one Circuit board (2) and the at least one metal core circuit board (3) are electrically connected to one another at least in an active operating state of the lighting device (1) via wiring means (6) comprised by the lighting device (1) and in particular are coupled so rigidly that the at least one circuit board (2) extends in an area behind the at least one metal core circuit board (3), which adjoins an underside of the metal core circuit board (3), which is formed opposite the top of the metal core circuit board (3), characterized in that the at least one metal core circuit board ( 3) comprises a recess and/or recess (7) and the lighting device (1) comprises an adapter element (8), wherein at least in the active operating state of the lighting device (1) the wiring means (6) are in the recess and/or recess (7 ) are arranged freely, in particular at a distance from the metal core circuit board (3) on the circumference, and form an electrical connection between the at least one circuit board (2), in particular the conductor tracks of the at least one circuit board (2), and the adapter element (8), wherein the adapter element (8) in turn realizes an electrical connection to the at least one metal core circuit board (3), in particular to the conductor tracks of the metal core circuit board (3) and/or indirectly via the conductor tracks of the metal core circuit board (3) to the lighting means (4). lighting device Claim 1 , characterized in that the wiring means (6) are designed as a pin strip (9) and / or that the recess and / or recess (7) is dimensioned such that a required insulation resistance between the wiring means (6) and the metal core circuit board (3 ), in particular a metal core (10) of the metal core circuit board (3), is maintained in order to avoid voltage flashover. lighting device Claim 2 , characterized in that the pin strip (9) comprises at least two pin contacts which are electrically insulated from one another and spatially positioned in a row and which are in particular designed to be rigid and/or inflexible. Lighting device according to one of the preceding claims, characterized in that the adapter element (8) is designed as a wiring board or as a circuit board (12), in particular as a single-layer circuit board. lighting device Claim 4 , characterized in that the wiring board or circuit board (12) has a plurality of openings for receiving and electrical connection bind, in particular through-contacting, the wiring means (6), in particular the pin strip (9). Lighting device according to one of the preceding claims, characterized in that the at least one circuit board (2) and/or the at least one metal core circuit board (3) have an annular contour and/or floor plan in plan view. Lighting device according to one of the Claims 4 until 6 , characterized in that the wiring board, in particular the circuit board (12), comprises a plurality of contact areas (13a-c) on at least one side surface (14a-b), which are designed and / or arranged so that in the active operating state, in particular by means of solder, an electrical connection can be made to a plurality of soldering pads formed on the top of the at least one metal core circuit board (3) in order to form an electrical connection via the conductor tracks of the metal core circuit board (3) to the lamps (4). lighting device Claim 7 , characterized in that the plurality of contact areas (13a-c) comprise an electrically conductive layer (15), in particular a metal layer, on the outside. lighting device Claim 7 or 8th , characterized in that the plurality of contact areas (13a-c) each comprises an arcuate section which is formed radially inwards. Lighting device according to one of the Claims 1 until 9 , characterized in that the recess and/or recess (7) in the at least one metal core circuit board (3) is designed to be closed on the circumference and/or that the recess and/or recess (7) depict the outer contour of the wiring means (6).

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